u/IMDLabs

I realized I'd never actually posted a picture of any of my builds, just some of my software stuff, so here's the first, slightly-modified, build I did, with both a 4x20 LCD, and then a 2x20 VFD.

I'm using a picoRom here to make programming easier, though it uses a 27CXXX pinout instead of 28CXXX, so two quick wiring changes are needed.

And I am running the serial port at 115.2kb/s.

The LCD is just any-other 4x20 HD44780 unit via Amazon for <$10 (you want one without the invariable-included I2C adapter board pre-soldered). Same interface and pin-out as the stock 2x16 display. I added another pot to control the backlight brightness, since I like the black/green displays best with little/no backlighting.

The VFD is from Newhaven Display, via Mouser, specifically this part (~$53).

It can run in a couple of different modes, but the default parallel M68 interface is pin and command compatible with the HD44780, it just assumes a 40 character line length rather than 20. So, it'll just drop-in (electrically at least, you may have to rearrange things for it to fit)

I wasn't paying attention to the size of the thing when I bought it, and it's, well, BIG.

There's a smaller version, but that only has double-row header pads, where this one has both that and a single-row 18-pin set of pads (first and last pins not used, and the A/K connection isn't either, so you just need 14 pins, starting from pin 2).

Next up will be to switch to a 4x40 Noritake VFD, or an 8x80 if I can find one, but as those are rather spendy I wanted to get this going first.

As part of my 2nd "Ben Eater 6502" build (a lightly modified version of the original), I extended my (already extended) version of Ben's "Arduino Monitor" to include full 65C02 decoding.

Effectively, it prints a disassembly as the code runs (see right-most column).

When it first encounters an OPCODE (indicated by the 65C02's SYNC line going high), it outputs the opcode and addressing mode, then, when it has completed the decoding in sync with the 6502's execution, it outputs the completed instruction; which includes target addresses for branch, JMP and JSR instructions.

Details, code, and the additional connection (to pin 7 on the 65C02) are all in the repo.

After building Ben's 6502 computer, and having gotten to the point it was running his build of MS-BASIC, I wanted to play around with some period-software for it.

That lead to (among other things) me starting to port the programs from "101 BASIC Computer Games" (which are in various pre-MS-BASIC dialects of BASIC), so they would "just run" on Ben's design.

If you're interested, they're here (GitHub) ... and I'm about 1/3 done with the 101, but figured they might be interesting to others. More details in the repo itself.

There are a few other related bits there too, such as an enhanced version of Ben's Arduino monitor program, and my fork of his MS-BASIC build that doubles the size of the token table (so you can add more than a handful of custom BASIC commands).